PAPER Peripheral neuropathy in hepatitis C virus infection with and without cryoglobulinaemia

Objectives: Hepatitis C virus (HCV) infection is often associated with cryoglobulinaemia (CG). Periph-eral neuropathy (PN) is a comparatively common complication of CG associated with HCV infection and it is thought to be attributable to nerve ischaemia. Only few HCV CG patients with PN have been reported. The recent finding of HCV RNA in nerve biopsy specimens has suggested a possible direct role of HCV in the pathogenesis of PN. The authors studied 51 HCV patients to determine the preva-lence of CG and to clarify the possible mechanism by which HCV determines the PN. Methods: All the patients were studied clinically, by laboratory tests and electrophysiologically. Twenty eight patients underwent sural nerve biopsy where both morphological and morphometric evaluation of the biopsy specimen was performed, as well as statistical analysis. Results: CG was found in 40 of 51 cases (78%). Polyneuropathy was significantly prevalent in CG+ patients compared with CG − (18 of 40 compared with 1 of 11 patients; p=0.01). HCV CG − patients more frequently developed well defined mononeuropathy or multiple neuropathy when compared with HCV CG+ (10 of 11 compared with 22 of 40; p<0.03). HCV CG+ patients showed significantly higher proportion of rheumatoid factor positivity (p<0.001) and low C4 levels (p=0.001). Nerv